Note: Descriptions are shown in the official language in which they were submitted.
r - ~
~Z52
1 ~AC~C~O~N3 Dr I~E I~V~ O~
2 Field of the Invention
~_, .
3 This lnvention relates to a combination steam
4 reforming-hydroconversion process for ligh~ hydrocarbon .
feeds wherein the hydrocarbon and s~eam are passed over a
6 sulfur-resistant catalyst which performs the dual fu~ction
7 of steam reforming and hydroconversio~ of the ~eed. More
~ particularly, this invention re~.at2s to a process for steam
g reforming and hydroconverting a rela~iYeiy light hydrocarbon
that is rslatively lcw in hydrogPn and high in sulfur, whlch
11 comprises passing steam and the hydrocarbon over a sulfur~
12 resistant catalyst ccmprising moLybde~um on a base selected
13 from the group consisting of {a) a high surface area alumina
14 base or (b) an iron oxide-chromium oxide base, said cata- :
lyst having been redu~ed and sul~ided prior to use, whereby
16 the steam reformin~ and hydroconversion are achieved in the
17 same reaction zone. --
18 Desc on o~ the Prior Art_
19 Steam reforming is well known to those familiar
in the ar aa a process or prod~cing hydrogen or hydrogen~
21 con~aining gas mixtures by conver~ing hydrocarbons with
22 steam. The hydrocarbon reac~s wi~h steam to form carbon
23 monoxide and:hydrogen in a gasifLcatLon reaction. The c~r~
i 24 bon monoxide is then reduced to a low level by a water gas
~ 25 shi~t reaction, whLch also produces more hydrogen. The two
$'~
1 reactions combine i~ steam reforming as illus~rated by the
2 following equaticns.
3 Ste~m re~orming: CnH2n ~ 2nH2o -~3nH2 ~ nC2
4 3 a) gasificationo CnH2n ~ n~2~ 2nH2 -t nCO
S + ~ wate~ ~s shit: nCO + nH2O-~ nH2 ~ nC02
6 O~e of the more commonly used catalysts for
7 stesm reorming is nickel oxide. NickPl oxide catalysts
8 are very reactive and steam resistant. Unfortunately~
~ however, ~hese catalysts are not rasistant ~o sulfur and,
consequently, their catalytic ac~ivity rapidly diminishes
11 to an unacceptably low level in the presen e o~ sulfur~
12 containing hydr~c~rb~ns. Pla~int~ and other noble metal
13 containing catalysts are also quite active for s~eam
14 re~rming hydr3carb~n fractions, but these too are rapidly
15 poisoned by relatiYely sm~ll qu~ntities of sulfux in th
16 feed. Cataly~ts cos~nonly llsed for the w ter gas shift
17 reaction include ironJc~romi~ ~xide and zinc/copper oxide
18 catalysts, while ~he m~re efflcien~ hydr~genation ca~aLys~s
19 con~ain one or more noble ~e~als. Tnese catalysts are also
poisaned and de c~l~ated by sulfur. ~nfort~cn~tely, ~any o
21 ~he well known sulfur tolerant hydrogen t~on catalysts are
22 deacti~ated i~ the presence of stea~ and are therefore
23 totally ~nsui~ ble ~n th~ stea~ reforming process.
24 ~ :The petroi~u~ lndu~t~y i5 incr~a3inOly turning
to:co~ r sands and ~ea~y crudes a~. sources f~r fu~ure
26 raw materi~LsO Feed stccks de~ived fro~ th~se heavier
.
27 m~terials are quite naturally ~e2~ie~ but k~e~ are also
28 more hydrogen deficient ~nd ~Ligher in ~ulfur ~nd nitrogen
29 than eed stoc~cs derived fr~-L~ ~ore corlver~ti~nal crude oiLs.
Thes~ heavier~eed 9~0cks tberef~re req~ire a considerable
:
5~ ~
amount of upgrading to usable products, such upgrading being
accomplished by various hydroconversion reactions such as
hydrodesulfurizing and hydrogenating, both of which require
large volumes of hydrogen and consequently result in very
high processing cos~s. One way of processing such feeds is
to pass the sulfur-containing feed to a first zone wherein
sulfur is removed via contact wi~h a hydrodesul~urization
catalyst, followed by a steam reforming zone wherein the
desulfurized feed is contacted with steam and a catalyst
to convert a minor portion of the feed to hydrogen, followed
by passing the feed and hydrogen from the steam reforming
zone to a third zone wherein the unsaturated portions of
the feed are saturated by catalytic hydrogenation. Further,
steam reforming is endothermic in nature requiring heat
input to the reaction zone, while hydrogenation is exothermic.
It is apparent therefore, tha~ i~ would be a signi-
ficant improvement to the art if one could develop a process
and steam and sulfur-resistant dual-function catalysts
which would permi~ combining the endothermic hydrocarbon-
steam reforming reaction to produce hydrogen and, at the
same time, allow in si~u utilization of the hydrogen pro-
duced by the steam reforming to saturate the olefins present
in the feed and hydrodesulfurize same, all in the same re-
action zone. This would eliminate the need for a separate
source of hydrogen, eliminate the need for the plurality of
reaction zones heretofore required for such processing and
also result in substantial energy savings, because the
exothermic hydroconversion reactions would provide at least
a portion of the heat required for the endothermic steam
reforming. ~`
~1 ,
-- 4 --
b~Y~~
2 It has now been discovered that one can achieve a
3 process combining hydrocarbon s~eam reforming and hydrocon-
4 version processes for sulfur and ole~in containing, light
5 hydrocarbon feed streams wherein the processes all occllr in
6 the same reac~ion zone, which comprises passing steam and the
7 hydrocarbon feed into a steam hydroconversion zone over a
8 dual-function catalyst comprising molybdenum o~ a base selected
9 rom the group consisting of (a) a high surface area alumina
base and (b) an iron oxide-chro~ium oxide base, said cataly$t
11 having been reduced and sulfided prior to use. Essential to the
12 understanding and practice of this invention is the fac~ that
13 no external hydrogen needs to be added to the steam hydro-
14 conversion zone. Hydrogen is produced in the steam hydrocono
version zone via an endothermic hydrocarbon-s~eam reforming
16 reaction and this hydrogen so produced is used in situ to
17 saturate olefinspresent in the feed and hydrodesulfurize same.
18 For the sake of brevity, ~he combination of steam reforming
19 and hydroconversion processes~ both of which occur in the same
reaction æone (steam hydroconversion zone) will hereinafter
21 be referred to as steam hydroco~versionIt has also been
22 discovered that the addition of minor amounts of alkali or
23 `al~aline earth metals to the catalyst will greatly improve
24 its life.
By steam re~orming is meant the combina~ion gasifi-
26 ca~ion plus water gas shit described supra, wherein o~efins
27 in the hydrocarbon stream react with steam to produce carbon
28 dioxide and hydrogen. Hydroconversion processes refer to
29 hydrodesulfurization of the feed and hydrogenation of the un-
saturated olefins present therein, along with some mild hydro-
31 cracking and attendant hydrogenation o the hydrocrackate and
~ ~ ~52~
1 wherein ~he hydrogen consumed is that produced by the steam re-
2 forming reaction. The following equations illustrate the steam
3 hydroconversion (steam reforming plus hydroconversion) of
4 propylene to form propane, wherein the maximum ~heoretically
obtainable yield at 100% conversion is 90 mole % of propane.
6 (a) steam reforming
C3H6 ~ 0.6 H20 ~ 0.9 C3H~ ~ 0.3 C02 + 0.9 H2
8 (b) hydrogenation
3 6 0.9 1~2 ~ 0.9 C3H8
~c) overall
11 C3H6 ~ 0-6 H20 --~ 0.9 C3H8 ~ 0.3 2
12 Catalysts useul in ~he process of the instant
13 invention c~mprise dual function stean hydroconversion
14 catalysts that are resis~ant to both steam and sulfur, said
catalysts comprising molybdenum alone or in admixture with
16 cobalt as the active catalytic metals on either a high
17 surface area alumina base or on an iron o~ide-chromium
18 oxide base, said catalyst having been reduced and sulfided
19 prior to use. Additionally, it has been found that the
efective life o~ the catalyst is greatly increased if
21 the catalyst is promoted wi~h small amounts of one or
. ....
22 more alkali and/or alkaline earth metals.
23 Although it is pre~erred that the catalytic metals
24 initially be present on the catalysts as sulfides, said metals
may also initially be present on the catalyst as oxides, re-
26 duced forms of the metal or as mixtures o these and othex
27 forms. What is important to the operation of the instant
: .
28 invention is that the catalytically active metals be converted
29 to the sulfide form either in t~e manufacture of the catalyst,
.
by pretreating same prior to its use in the operation o the
31 instant~inven~ion or by in sit~ conversion of the oxide or
32 reduced fonms to the sulfides via sulfur-containing feeds.
'
.- - - - . ' ' :
,
.. . .. . .
1 These metals will be present ~n the catalysts in
~ catalytically active amo~s3 e.g., from about 5 to about 50
3 wt. % (calculated as metal), pre~erably ~rom about 10 to 40
4 wt. % and most preferably ~rom about 15 to 30 wt. % based on
the total weight of ~he catalyst when the activ me~al is
6 molybdenum. Particularly preferred cat~lysts include
7 (a) about 25 to 50 wt. % molybdenum sulfide and (b) 15 ~o
8 30 wt. % molybdenum sulfide along with 2 to 10 wt. % cobalt
9 sulfide based on the total weigllt (dry basis) of ~he catalyst
10 cornposition.
11 The exact method used to sulfide ~he catalyst is no~
12 importan~ and the art recognize5 several ways in which one
13 may sulfide such ca~alysts. Xllustrative examples include
14 (a) using hydrogen suLfide with hydrogen~. (b) using carbon
disulfide with hyd~age~ or in a hydrocarbon feed in the pres-
16 ence of hydrogen and (c~ using a sulur-containing feed in
17 a ~educing atmosphere~ .
18 In addition to the catalyticall!y ac~ive ~etal com-
19 ponents, t~e catalyst may also contain minor amounts o other
Group VIB and VIII metals such as tungsten, platinum, rheniumJ
21 and nickel which,while not necessarily catalytically active
22 in the instant invention, ha~e been found not to exert a
23 deleterious effect to the operation of same. As much as 5
24 wt. % of these other metals may be present on the catalyst
25: without incurring any deleterious ef~ect.
26 The ratio of molybdenum to cobaLt.in catalysts
27 containing both of these metals generally ranges rom 1.5/1
28 to 20/1,~ preferably 3~5/1 ta 10/1 and most preferably rom
29 4.5/1 to 8.5/1. If minor amounts of other group VIB or VIII ~ -
30 metals are present, the ratio of molybdenum to these other
31 metals will gene~al:ly range ~rom about 50/1 to 5/1 and pre-
32 ferably rom 25/1 to 10/1.
- 7 -
1 The alumina support material employed in the cata-
2 lysts of ~his invention is most preferably a high surface
3 area type of alumina having a surface area of from about 100
4 to about 400 m2/g (s~uare meters per gram) and most prefer-
ably ~rom about 150 to abou~ 350 m2/g. A particularly pre-
6 erred alumina support is eta alumina having a surace area
7 of approximately 300 ~2/g, Although the presence o~ silica
8 in the al~nina support is detrimental to the process of the
9 ins~ant invention9 the support may contain up ~o about 5 wt~C/o
sili~a (based on the total weigh~ of the support) without in-
11 cur~ing any serious adverse effects to the processes of the
12 instant invention. As hereinbe~ore stated, supra, the cata
13 lyst life is greatly ~mproved by ~he addition of minor
14 amounts of alkali a~d/or alkaline earth me~als illustrated by,
but not limited to, metals such as barium and cesium~ In
16 general, these metals will range from about 1 to 10 wt. %
17 (based on total catalyst weight~, and pre~erably from about
18 2.5 to about lOZ~ The alkali and/or alka~ine eart~ metals
19 are ge~eralIy incorporated into the catalyst base in the
form of acetates or carbonates.
21 A particularly preferred catalyst useful in the
22 process of the instant invention comprises from about 25 to
23 about 50 wt. ~/a molybdenum sulfide and from about 2 to 8 wt~/o
~4 cesium carbonate based on the to~al weight (dry basis~ of
the catalyst, supported on an eta alumina base.
26 The iron oxide-chromium oxide base or support will
27 contain from about 1 to 15 wt. % chro~ium oxide (calcula~ed
28 as Cr203) with most of ~he balance being iron oxide (calcu-
29 lated as Fe203). These supports are of the type in U.S.
30 2,662,063, the disclosures of which are incorpora~ed herein
31 by reference. The surface area o this type of support
1 generally ranges around 100 m2/g. A preferred cataLyst
2 useful in this inven~ion will comprise from about 20 to
3 30 wt. % molybdenum (based on ~otal ca~alyst weigh~, dry
4 basis) on the iron oxide-chromium oxide support.
~ The steam hydroconversion catalysts of the ins~ant
6 invention may be preDared by any conventional manner known
7 in the art. For example, a commercial alumina catalyst base
8 of the desired surface area may be soaked in a solution of
9 ammonium molybda~e CGrl~aining the de~ired amount o~ molyb~
denum. The water is removed in a ~lash evaporator and the
11 resulting catalyst is dried at 230F. and calcined in air at
12 about 930F. Prior to use in the laboratory, it has been
13 found convenien~ to reduce and sulfide the molybdenum by
14 passing a mixture of 10% H2S in hydrogen over the catalyst
at about 930F. Up to 50% iner~ gas may be added i~ this
16 last step to prevent overheating due to the exothermic
17 nature of the reaction.
18 The iron oxide-chromium oxide support may be pre-
l9 pared by coprecipitating a mix.tur~ of chramous an~ ferrous
hydroxides by the addition of sodium hydroxide solution to
21 an aqueous solution o errous sulfate and chromic acid
22 containing the desired amount o~ iron and chromium. The
23 hydroxide precipitate is air dried at up to ~bout 1100F
24 dùring which time the hydroxides are oxidized to chromic
and ferric oxides. The resulting material may be pelletized
26 or extruded by standard methods. Molybdenum is then deposi-
27 ted on this base by the method described above for the
28 alumina base and the resulting catalyst calcined, reduced
29 and sulfided as previously described. During the suliding
30 step the chromium and iron oxide ma~ also be converted to .. :
31 their sulfides. Alternatively, the chromium oxide may be
32 deposited on the iron oxide.
_ 9 _
1 In accordance wi.th the instant invention, the
2 aforedescriLed ca~alysts are employed to steam hydroconvert
3 li~ht, sulfur containing feed stocks by contacting said
4 feed stocks with the catalyst in the presence of steam at a
temperature in the range of from ~out 500 to 1200F. and
6 preferably 750 to 1000F~; a pressure in the range of from
7 about 0 to 1000 psig and prPferably O to 600 psig; a steam
8 to hydrocarbon mole ratio of from about 0.5 to 10 and pre-
g ferably 1.5 to 6.5, with a gaseous hourl~ s~e~e velocity
10 (V/V/Hr . ) in the range of from about 20 ~o 200 and pre~er-
11 ably from about 40 to 150 Y/V/Hr.
12 Hydrocarbon feeds useful in the process o the
13 instant invention are the relatively li~h~er pctroLeum
fractions containing unsa~urated olefins, ranging Xrom those
15 hydrocarbons normally gaseous at room ~empera~ure and pres-
16 surey such as propylene~ through light, steam cracked naph-
17 thas having a boiling range of from about 140 to 200F. up
18 to an including feeds such as coker naphthas boiling in the
19 rang,_ of from about 140 to 4 00F. In general, these feeds
20 may have sulfur contents up to about 0.5 wt~ % and may h~ve
21 levels of unsa~uration such that the Bromine Number ranges
22 from about 50 to 200. However, both the sul~ur content and
23 unsaturation ma~ be appreciably higher as evidenced by the
24 fact that the catalys~s of the instant invention were ef-
25 fective in steam hydrocon~erting propylene to propane in the
26 presence of 4 wt. % H2S. Propylene has a theoretical
27 Bromine Number of 380. Further, feeds derived from the
~8 heavier materials such as heavy crudes, tar sands, shale oil,
~9 coal, etc. will contain considerably msre unsaturated olefins
30 and sulfur than those deri~ed from more con~entional crude
31 oils. Klthough feed stocks rela~ively low in sulfur or
32 containing no sulfur at all may be steam hydroconverted with
- 10
1 the catalysts of ~his inventiona one of the ou~standing
2 features of same is the ability to steam hydroconvert feeds
3 containing over abou~ 50 ppm of sulfur by using a single,
4 dùal-function catalys~ with both the steam reforming and
hydroconversion processes taking place simultaneously in
6 the same reaction zone without having to add any external
7 hydrogen to the reac~ion zone.
8 DESC~IPTION OF T~IE PREFERP~ED ~i30DL~IENT
9 The following examples urther lllustrate the
present invention. Unless othe~ise specified, all pex-
11 centages and parts are by weigh~.
12 EXAUPLE 1
13 Steam hydroconversion cata].ysts in accorclance with
1~ the invention were prepared as follows:
A number of com~ercially available catalysts
16 ~listed in:Table 1) were impregnated with various amountc
17 Of metals, including rhodium, moIy~denum and rhenium as
18 shown in the Table, by soaking same in aqueous solutions of
lg the desired metal5 followed by flash evaporation ~f the water
and air calcLning for one hour at gOOF~ Some of the cata-
21 lysts were not modifled~ while the rhenium on alumina cata-
22 lys~ used for run 21 was prepared by soaking a commercial
.
23 alumina in a solution of rhenium trichloride followed by
24 flash evapora~ion of the water and air calcining for one
hour at 900F. All of the catalysts were reduced and sul~
26 fided by contact with a 10/1 mixture of H2/H2S for one hour,
27 or until H2S breakthrough, at a tempera~ure of 900F. ~nd
28 atmospheric pressure in order to convert the catalytic metals
29 thereon to the sulfide form. During sulfiding it was occas-
ionally necessary to dilu~e the H2IH2S mixture with an inert
31 gas in order to maintain the temperature at 900F., due tO
32 the exothermic na~ure of the reaction.
~.~L2~
- 1 1 ~
l T~e sulfided catalysts were then contacted with
2 steam and a propylene stream containing 4~/O H2S in the ratio
3 of 4/l steam/propylene, at a t~mpera~ure in the range o
4 750 to 950F., at atmospheric pressure and a space velocity
o 120 V/V/Hr. T~e H2S was added to ~he ~eed in order ~o
6 determine the resistance of the various catalysts to sulfur
7 and amounted to 40,000 ppm of sulfur in the hydrocarbon Feed
8 stream.
9 Table 2 contains t~e resu].~s o~ ~he experiment
10 which are expressed as the percent o~ propane in ~he ofi or
11 product gas~ The noble metal and rhenium catalysts, both
12 o~ which are use~ul ~or steam reforining, t~ere relatively
13 ine~fective, while the molybden~n containing catalysts
14 operated e~feci:ively in the sulfur containing strea~ and
steam hydroconverted some of the propylene to propane.
16 TABLE 1
17GATALYST COMPOSITIONS FOR
18STEAM HYDROCONVERTING PROPYLENE
19 ~lm . . .
20 No.Catalysts and C m~ sitionsa
21 1Cyanamide CK-303 (0.3% Pt. on A12O3~ Impregnated
22 with 0.3% Rh~
*
23 2 Nalco 471A (3~5% CoO and 12.5% MoO3 on A1203).
24 3 Girdler T-828 (2~5~/o NiO, 3% CoO and 10% MoQ3 on
26 llGirdler G-3A (l~/o Cr203 on Fe203) Impregnated
27 with 10% ~o.
28 12Girdler G 3A (10% Cr2O on Fe2O ) Impregnated
29 with 25/~ Mo. 3 3
- 30 13Girdle~ G~3A (10% Cr2O3 on Fe203) Imp~egna~ed
31 with 5% Mo.
32 19Harshaw Mo-1201 (l~/o I~1003 on A1203)-
33 212% Re on A1203.
34 283, 5/0 CoO and 14% MoO3 on A1203
Notes: a Metal con~ent as oxide based on total.catalyst
36 composition.
* TM
..~
- 12 -
Tab
2 EFFECTIVENESS OF CATALYS~S IN
3 STEA~ HYDROCONVE~TIMG PROPYLENEb
4 ~W ~
All catalysts reduced and sulided in
10/1 H2~H2S pFior to useO.
7 ~un N~.a ~ C3~,C~
8 1 1.1
9 2 7
3 7.6
11 ll 7 .
12 8 . 3
13 13 7 . 5
14 19 `.7.8 . ~
21 2.2 .
28 13 . 7
7 No~es- a Ca alyst compositions correspond eo ~hosa in
19 b 4 w~.~Z H~S in ~propylene feed~
.
2.1 In ~his experiment, as in ~Example 1, supra, a
22 number of comstercially a~aiLable catalyst suppoxts or :bases
23 were impregnated wit~ 25% molybden~m which was then reduced,
24 sulfided and contacted with ~ the same feed stream and at the
25 same conditions as in Example 1. The results are shown in
26 TabLe 3 and suggest tha~ m~re e~fective stea~h hydroconver-
27 sion oP propylene to propane is obtained if one employs
28 both higher sur~ace area s~ippcr~s and snp~orts ~'~at are
2~ primarily alumina.: The ;~ost ef~ective catalyst in this
:
, .. ... .
~ 13 -
1 experiment was 25~ molybdenum on eta alumina.
Table 3
425% molybdenum reduced and
5sulfided on support
6Sura~e Area % Propane in
7 ~ ~ Product Gas_
8 Davison 970 (87/13 SiO2/A1203) 100 3.5 ;~
9 Harshaw*Al-3428 (A1203) - 176 19~3
Davison (~ oA1203~ 300 24.7
11 ~,
12In this experimen~ samples of the 25% molybdenum
13 on e~ alumina c~talys~ were impregnated with alkali and
14 alkaline earth me~als by sc~ing the molybdenum on ~lumina
catalyst in an a~ue~us solu~ion of ~he acetate, carbona~e
16 or hydr~xide o~ the alkali or alk21ine earth~metal which
17 contained t~e desired amount o~ metal, removing the~water
18 by flash evaporation and drying and calcining the impreg-
19 nated catalysts at temperatures up to 500~C (930F~ Lor one
hour in air.
2L Table 4
22IMPRO~E~N~ OF GATALYST LIFE BY AD~ITION OF
~3ALKAIX AND ALI'~LINE E~RT'~ ~TAL5
_ __
24 Added Metal1. _ c~_ ~c~ l~
~ ~None 37
26 5% ~ 2~ -:
27~ SZ Cs 13
28 ~.5% Cs ~ 20
29 The impregnated catalysts were reduced and sul~ided using
* TM
.... . ~ ' "
~ $
- 14 -
1 the method ou~lined ~n ~xample 1. The sulfided catalysts
2 were then contacted wi~h a 3/1 steam/propane feed stream
3 a~ about 750~, atmospheric pressure and a space velocity
4 of about 60 V/V/Hr~ The effect of th~ alkali and alkaline
S ear~h metals was determined by measuring ~he loss of
6 catalytic activity for steam hydroconverting the propylene
7 to propane after between 3/4 and 2-1/2 hours onstrPam.
8 The results in Table 4 show that bo~h alkali and
9 alkaline earth me~als are effective in improving ~he
catalyst life.
11 ~,~ ,
12 This illustrates the effectiveness a the inven-
13 tion in steam hydrocon~erting a sour, steam cracked naphtha.
14 A 10% molybden~m on ~ alumina catalys~ sold commercially ~:
by the Harchsw Chemical Company as Mo~1201 for hydrogena~
16 tion, dehydrogenation and hydroforming was utilized. This
17 catalys~ could be prepared by soa~i~g alumina of desired
18 surface in æmmoniu~ molybdate solution followed by flash
19 evaporation of ~he water and drying ~nd calcining in air.
The catalyst was reduced and sulfided prior to
21 use according to the procedure outlined in Exampla L. It
2~ was then contacted with a sul~ur~containingS saur, steam
23 cracked~naphtha feed at a temperature of:950F9 a pressure
24 ~of 600 psig, normalized space velocity of 140 V/V¦Hr~ and
a steam/~eed mole ratio of 4/1. The results given in
~6 Table 5 show a substantial decrease in b~th sulfur content
27 and Bromine Number~ i
- 15 -
~Table 5
2STEAM HYDP~OCONVERTIt.~G
3SOTJr~ STEAI~I C~CI~ED ~7AP~ITHA
__ ____
4 Feed Product
5Sulfur, ppm 500 250
6Bromine Number 90 20
~ ~ .
8. ~his illustrates the effect o~ different space
9 velocities and steam mole ratios cn ~he steam hydroconver-
lQ sion o propylene to propaneO
11 A 25% molybdenum on eta alumina ca~alyst was
12 prepared by the method o~ E,v.ample 3. Propylene and steam
13 i~ varying mole ratios were passed o~er the cat~lyst at
1~ atmospheric pressure and-750F. The pl:opylerP eed con-
~ailled 4% H2S. T~ble 6 ~Plow sho~?s that highest )T~e~ds
16 of propane were obt2ined at a ~aseous hourly space
17 velocity o 120 when the mole ratio of steam to prop~rlene
18 ~as 1.5. Simllarly high yields wPre obtained at a low
1~ space velocity of 40 V/V/Hr ~hen 6.5 m31ec of steam were
added. The catalyst was regenerated with air &nd resul-
21 ~ided between each different conditior10
22 Table 6
23 C3 Space Velocity H20/C~ ~/O Propane
24 V/V/~ ~ole l~atio in ~roduct
.
120 ~ 10,7
26 " 4 24.7
27 " 2 26.?
28 " 1.5 3~.9
29 " 0.8 30.
~40 6.5 39.9
.. . ... .
,
~ 16 -
1 ~
2 This illustrates ~he efect of pressure on the
3 steam hydroconversion of propylene to propane.
4 A 25~ molybdenum on eta alumina catalyst was pre-
S pared as previously descr~bed. Propylene containi~g 4%
6 sulfur as hydrogen sulfide or butylmercaptan was passed
7 over the catalyst at 750F at~tmospherie pressure and at
8 300 psig. Table 7 shows the conversion of propylene,
9 selectivi~y of the reac~ion to propane and propane yields
when operating at 40 V/V/Hx at a~mospheric pressure and
1} 120 V/V/Hr at 300 psig.
12 ~a~
13 H20/C3- Propylene Propane
14 Press C~' Sp Vel Mole Conver- Selec~ Propane
E~ V7VJHr Ratio ~ y~_~ Yield %
16 0 40 6.5 65~5 65~2 42.8
17 300 12~ 6.5 98.0 7805 77~0
